The present invention relates to a self-contained, compact transceiver tile structure, or tile, which is employable in and with respect to a system, apparatus, and methodology involving dielectric microwave scanning of a human subject, and in particular, to such scanning which is done for the purpose of detecting, in relation to baseline physiologic response data, and according to defined screening criteria, notable differences, or anomalies, in relation to a given individual's “dielectric signature”. Put in another way, the transceiver tile structure of this invention is especially suited for use in a substance-scanning environment (a dielectric scanning environment) wherein the contained transceivers, and their supporting operational circuitry, are constructed to perform substance-scanning differentiation between physiology (human physiology) and non-physiology. The term “transceiver” is used herein with a definition which refers to a device which simultaneously transmits and receives signals.
While there are many substance-scanning (or screening) applications in which the integrated transceiver tile structure of this invention finds substantial practical utility, two specific such applications are particularly noted herein, and one of these is employed as a principal model for discussing and explaining the structure and operation of this invention. These two applications include (a) security detection, or scanning (screening), at locations such as airports for the purpose of detecting weapons, contraband, etc., and (b) authorized access control for personnel in sensitive areas, for example, in relation to research and development areas within a business. Many other useful applications will come to mind to those generally skilled in the art.
A preferred embodiment of the tile of the present invention is described herein in relation to a scanning system which departs from, and offers certain improvements over, a like, predecessor system and methodology that are fully illustrated and described in above-mentioned U.S. Pat. No. 6,057,761. These improvements, which exist in certain areas involving both mechanical and electrical aspects of the previously illustrated scanning process and structure per se, result in the present invention having certain preferential utility in particular applications, such as in applications involving airport-security screening areas, where a very efficient, high throughput of people needs to be accommodated without compromising scanning resolution and effectiveness. In terms of how scanned data is ultimately read (monitored and evaluated based upon the operation of the tile structure of this invention) to detect dielectric anomalies that are important to detect, substantially the same technology which is described in the just-mentioned '761 patent is also employed, for the most part, in the improved system version which is disclosed in this document.
By way of further background, and regarding the dielectric scanning (or screening) process which is implemented by the tile structure of the present invention, as a general statement respecting the relevant physics, all materials have what is known as a dielectric constant which is associated with their physical, electrical (electromagnetic and electrostatic) properties. As a consequence, when exposed to different wavelengths and frequencies of microwave radiation, each material produces a reflection reaction, or response, to that radiation, which response, in nature, is uniquely related, among other things, to the particular material's respective dielectric constant. By subjecting a material to controlled, transmitted, microwave energy, it is possible to interpret a material's reflection “response” thereto in terms of its dielectric constant. The term “dielectric signature” is employed herein to refer to this phenomenon.
Where plural, different characters of materials are closely united in a selected volume of space, microwave radiation employed to observe and detect the “dielectric signature” of that “space” will elicit a response which is based upon an averaging phenomenon in relation to the respective dielectric-constant contributions which are made in that space by the respective, different, individual material components. This averaging condition plays an important role in the effectiveness of use of the present invention, and this role is one which the reader will find fully described and discussed in the above-mentioned '761 patent.
In a system and methodology of the type just above generally outlined and suggested, the tile structure of this invention is designed to direct microwave radiation into the human anatomy (at completely innocuous levels regarding any damage threat to tissue, body fluids, or bone) in such a fashion that it will effectively engage a volumetric space within the body wherein there are at least two, different (boundaried) anatomical materials, each characterized by a different dielectric constant, which materials co-contribute, in the above-mentioned “averaging” manner, to the “effective”, apparent “uniform” (or nominal homogeneous) dielectric constant of the whole space. As is explained in the '761 patent, by so designing the tile structure of the present invention and its operation to engage the mentioned at-least-two-material volumetric space inside the anatomy, the likelihood that a weapon, or an article of contraband, will, by the nature of its own dielectric constant, and/or its specific configuration and shape, and/or its precise location and/or disposition relative to the human body, “fool” the invention by masquerading as a normal and expectable anatomical constituent, is just about nil. Preferably the “penetration depth” of this internal anatomical space is about 2½-wavelengths of the system operating frequency as measured mechanically in material having the mentioned “normal” dielectric constant.
If and when a foreign object, such as a weapon, or a contraband object, is borne by a person, for example closely against the outside the body, the presence of this object will, therefore, and does, change the average dielectric constant of the material content of the volume of space (anatomy, of course, included) which is occupied, in a very non-normal-anatomical, and detectable, manner, by the mentioned microwave radiation. Definitively, the presence of such non-expected (non-anatomical physiologic) material significantly changes the average value of the effective, average and apparent, uniform, spatial dielectric constant, in accordance with the averaging phenomena just mentioned above, and creates a situation wherein a distinctly different-than-expected dielectric signature appears as a responsive result of microwave scanning transmission in accordance with the invention. This scanning or screening process is referred to herein as being a practice of substance-scanning differentiation between physiology and non-physiology.
Further describing important distinctions that exist between prior art conventional practice, and practice performed in accordance with the tile structure of the present invention, whereas conventional scanning systems are designed to look for and “identify” a rather large number of specific objects and materials (substances), the approach taken according to the present invention is based upon examining human physiology for physiologic irregularities/abnormalities which are not expected to be part of the usual human, physiologic, dielectric signature (within a range of course) that essentially all people's bodies are expected to produce. As a consequence of this quite different approach for scanning, the system and methodology practiced by the tile structure of this invention are significantly more efficient, and quicker, in terms of identifying weaponry, contraband, etc. problem situations. Any out-of-norm physiologic signature which is detected produces an alarm state, which state can be employed to signal the need for security people to take a closer look at what the particular, just-scanned subject involved might have on his or her person.
In this systemic and operational setting, the present invention specifically relates to a unique plural-transceiver, integrated, modular tile structure (tile) which includes plural, compactly stacked, piggybacked circuit boards (panels) or layer structure, in one of which are homogeneously molded, in a row and column matrix fashion, an array of common-material, microwave transceiver body structures. Appropriate circuitry (transceiver-function operational circuitry) generally described herein, and implementable in numbers of different ways which are well within the skill of those generally skilled in the relevant art, electrically interconnects the circuit boards, and functions to control and drive the operations of the transceivers in simultaneous transmission and reception modes of operation. The transceivers (also called antennae) are densely organized to contribute significantly to overall structure compactness. The transceivers in a tile are arranged in a defined row-and-column pattern which is important to operation, and when two tiles are brought into appropriate side-by-side adjacency this pattern forms an appropriate operational pattern continuum across the two tiles. A useful arrangement of the tiles indeed involves organizing plural tiles themselves into a row-and-column array, and such an array has been determined to be quite effective in a structure desired to “scan”, for example, airline boarding passengers.
According to an illustrative manner of utilizing the invention, for example in the setting of an airport, a kiosk-like unit is provided into which a party to be scanned steps through an open, subject entry-way which is defined by a pair of spaced opposing upright panels, each of which carries an array of integrated, self-contained tile structures, or tiles, each including combined, coaxial microwave transmitters and receivers (transceivers). These two panels effectively define an always open and exposed through-passage through the region between them, which region is referred to herein as a scanning zone, or chamber. These panels also define what is referred to herein as a panel-orientation-determined path for the passage of a person through the scanning zone. A complete scan of a human subject takes place in two stages, with, in one stage, these panels being located on one set of opposite sides of the body, such as on the left and right sides of a person, and in the other stage, the panels being disposed in a quadrature-related condition (having been rotated ninety-degrees) to perform a second scan which is taken along the two orthogonally related body sides, such as the front and rear sides of the person. Between these two scan orientations, the panels are rotated (as was just noted) through a ninety-degree arc, and in each of the two scanning positions, there is essentially no relative lateral motion which takes place between the panels and the subject standing between them.
A special processing feature of the illustrated system employing the present tile structure invention, with respect to the handling and scanning of large numbers of people, such as must be handled at airport security locations, is that the illustrated system allows for the creation, essentially, of two, generally orthogonally related lines of people waiting to be scanned, with successive people who are scanned entering the scanning zone, one after another, and alternately, from the heads of each of the two orthogonally related lines. A person to be scanned initially faces the scanning zone with a clear (see-through) view into (and through) that zone between the two panels.
With the person in place in the scanning zone, and disposed relatively stationary within that zone, the first scanning phase takes place to examine, sequentially, the laterally opposite sides of that person. This scanning phase is implemented by a special pattern of high-speed energizations of tile-borne transceivers organized into arrays in the panel-carried tiles of the present invention.
When such a first scanning phase is completed, and it is completed in a very short period of time, typically about 8-milliseconds, structure supporting the two tile-carrying panels rotates these panels through an arc of ninety-degrees, and stops them in the second scanning position relative to the subject, wherein the front and rear sides of the person are similarly scanned sequentially under a circumstance similar to that just described where the panels, and the subject between them, are again relatively fixed in positions with respect to one another.
The second scanning operation completes the scan process for the single subject now being discussed, whereupon that subject turns a corner to the right or to the left (this is illustrated in the drawings) depending upon which is considered to be the exit side from the scanning zone, and exits through the now-rotated, open (see-through) space between the two panels. The panels with the tiles of this invention are now positioned orthogonally with respect to the positions that they held when the first person just described was to be scanned, and the lead person in the orthogonally related other line of people now enters the scanning zone from the orthogonal location of that other line. Scanning of this next person takes place in much the same fashion just above described, except for the fact that, when the panel structure rotates through an arc of about ninety-degrees to perform the second scan of this “next” person, it effectively counter-rotates back to the position which it initially held in preparation for the previously explained scanning of the first person mentioned above. Scanning data is appropriately computer acquired from all scanning phases (two per person).
From the scanning data which is gathered with respect to each scanned person, that data is compared to a “map” or “schedule” of appropriate, physiologic, dielectric data relating to someone with a body type, height and weight similar to that of the person specifically being scanned, and any notable, dielectric-signature-related abnormalities cause an alarm state to be created which causes security people, for example, to call the particular subject aside for further and more focused scanning inspection. No photographic imagery is developed from any scanning data. Rather, one of the output qualities of scanned data includes the presentation, on a simple wire-form human anatomy shape, of one or more highlighted general anatomic areas that show where a detected abnormality resides. This presentation of data is easily readable and assessable with little personnel-interpretive activity required. Output data may also be presented in a somewhat grid-like, or checkerboard-like, field of light and dark patches whose lightnesses and darknesses are interpretable to indicate the presence of a detected dielectric, non-physiologic abnormality. This scanning process is fully described in the '761 patent and in the mentioned, prior-filed patent application.
Greatly facilitating a scanning operation as just described is the important compact and self contained transceiver tile structure of the present invention. As has been mentioned generally above, and as will be seen, this compact tile structure is formed with plural compactly stacked circuit board structures, the “front” one of which includes a generally planar body having molded into it the principal body portions of a plurality of transceivers organized into an orthogonally disposed row-and-column arrangement. While different specific organizations may be employed in accordance with practice of the invention, that which is illustrated herein as a preferred embodiment results in a cube-like tile structure having perimeter dimensions of about 10-inches by about 10-inches, and a stack depth, including three circuit boards, of about 2-inches or less. Extending from the fronts of the transceiver main bodies are elongate cylindrical stacks of parasitic elements. Preferably these elements are shrouded in the overall tile structure by an appropriate, radiation-transparent covering which gives the entire assembly of a tile a “cube-like” appearance.
As will become apparent and understood from the construction of the tile structure of this invention, an array of tiles, such as the arrays which are employed in the illustrative system described herein to demonstrate and explain use of the invention, can be assembled simply by bringing pairs of tile structures into side-by-side lateral adjacency with their “corners” aligned, and no matter which way a tile is oriented in the array, there will result what can be thought of as a tile functional continuum with respect to the appropriate operations of the transceivers in each tile. In other words, a very expansive array of transceivers can be assembled utilizing the tiles of the present invention based upon functional modularity which exists in the tiles, and which permits the tiles to be brought together in a fashion whereby it is not necessary that specific tile edges be brought into contiguity with specific edges of other adjacent tiles. Substantially any edge-to-edge aligned abutment will work appropriately.
Other features and advantages that are offered by the tile structure of the present invention will become more fully apparent as the description which now follows is read in conjunction with the accompanying drawings.